Air pump for aquariums

ABSTRACT

An air pump for aquariums to reduce noise and shrink the casing includes at least one air pump assembly in the casing. The air pump assembly has an air delivery duct communicating with a muffling chamber located on an outer bottom side of the base of the casing. Air discharged by the air pump assembly passes through a circuitous path in the muffling chamber. Thus noise can be reduced. The casing also can be shrunk to a smaller size.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an air pump for aquariums and particularly to a noise-reducing air pump that has a smaller size to supply air for aquariums.

2. Description of the Prior Art

The general aquarium requires an air pump to supply oxygen to the living things bred therein. The air pump compresses air to generate air suction and discharge operations. It is a high speed reciprocal operation and produces irritating noise which becomes an annoyance in the house. Many schemes have been proposed in the prior art trying to resolve this problem. For instance R.O.C. patent publication Nos. 519194 and 416488 (called prior references hereinafter) have a plurality of enlarged air discharge chambers on one side of an air pump to form a muffling chamber to overcome the noise problem.

While the prior references can reduce the noise, they create other problems, notably:

-   -   1. Adding the muffling chambers increases the size of the air         pump. The casing of the air pump assembly also is larger. As a         result, fabrication cost is higher. The product is not         competitive.     -   2. The larger air pump takes a lot of space in the aquarium. The         overall appealing of the aquarium is affected.     -   3. The muffling chamber is located on one side of the air pump         assembly. It is constrained by the limited space and cannot         provide desired noise reducing function.

SUMMARY OF THE INVENTION

In view of the aforesaid problems, it is an object of the present invention to provide an air pump for aquariums that can reduce noise and can be made at a smaller size. It has an air pump casing which houses at least one air pump assembly. The air pump assembly has an air delivery duct communicating with a muffling chamber located on an outer bottom side of the base of the air pump casing. Air delivered by the air pump assembly passes through a circuitous path in the muffling chamber. Thus noise can be reduced. The size of the casing also is smaller.

The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of the invention.

FIG. 2 is a perspective view of the invention.

FIG. 3 is a sectional view of the invention.

FIG. 4 is a schematic view of the circuitous path on the outer bottom side of the invention.

FIG. 5 is an exploded view of another embodiment of the invention.

FIG. 6 is a perspective view of another embodiment of the invention.

FIG. 7 is a sectional view of another embodiment of the invention.

FIG. 8 is a schematic view of the circuitous path on the outer bottom side of another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 through 4, the air pump for aquariums of the present invention includes a casing 1 and at least one air pump assembly 2 located in the casing 1.

The casing 1 includes:

a upper cap 11 which has a hollow housing chamber 110, an inner wall 111 with a plurality of fastening struts 112, 113 and 114 located thereon that have respectively an internal screw hole. The center of the upper cap is fastened to a top plate 115 through a bolt 116 which runs through a center hole 1151 and engages with a fastening bolt 114; and

a base 12 which is coupled with the upper cap 11 to form the casing 1. It has a plurality of apertures 1211 and 1212 corresponding to the fastening struts 112 and 113 to be fastened by a plurality of bolts 1221 and 1222. The base 12 has at least one anchor plate 124 on an inner side 120 to install at least one air pump assembly 2, and at least one opening 123 communicating with a muffling chamber 126 on an outer bottom side 125 of the base 12. The muffling chamber 126 has a hollow chamber 1260 formed by indenting the outer bottom side 125 and is covered by a bottom lid 128. The hollow chamber 1260 has a plurality of partitions T formed in a crisscross manner to divide the chamber into a plurality of small air compartments B1, B2, B3, B4 and B5. The neighboring air compartments B1, B2, B3, B4 and B5 communicate with each other through vents C1, C2, C3 and C4 to form a circuitous path L for airflow. Air is discharged through an air discharge duct 127.

The air pump assembly 2 includes an air pump 21 and an electromagnetic induction means 22 (this is a structure known in the art).The air pump 21 has a magnetic crank shaft 211 to compress a cap 212 so that air is drawn through an air inlet 2131 of an air chamber 213 and discharged through an air delivery duct 2132. The air delivery duct 2132 runs through a plug 2133 and is anchored in the opening 123 of the base 12.

By means of the construction set forth above, when in use, the crank shaft 211 of the air pump 21 is driven by the electromagnetic induction means 22 to compress and restore the cap 212 reciprocally to generate air suction and air discharge operations alternately. Hence air is continuously delivered through the air delivery duct 2132 and the opening 123 into the muffling chamber 126, and enters the small air compartments B1, B2, B3, B4 and B5 in this order through the vents C1, C2, C3 and C4 along the circuitous path L. The noise can be reduced. Finally the air is discharged through the air discharge duct 127 to supply the air to an aquarium.

Referring to FIGS. 5 through 8 for another embodiment of the invention. The casing 3 of an air pump set A′ houses two sets of air pumps 41 and 42 that is formed by coupling a upper cap 31 and a base 32. The base 32 has an inner side 320 to hold the air pumps 41 and 42. The air pumps 41 and 42 have respectively an air delivery duct 411 and 421. During operation of the air pumps 41 and 42, air is discharged through openings 321 and 322 of the base 32, enters a muffling chamber 326 on an outer bottom side 325 of the base 32. The muffling chamber 326 has a hollow chamber 3260 formed by indenting the outer bottom side 325. The hollow chamber 3260 has two circuitous paths L1 and L2 to direct airflow, and is fastened to a bottom lid 329. The circuitous paths L1 and L2 correspond to the air pumps 41 and 42. The circuitous paths L1 and L2 have respectively a plurality of partitions T′ to form a plurality of smaller air compartments E1, E2, E3, E4, E5, E6, E7 and E8 that are communicated by vents f1, f2, f3, f4, f5 and f6. Hence air passes through and is discharged through air discharge ducts 327 and 328 to supply the air for an aquarium.

In yet another embodiment of the invention, the upper cap 31 of the air pump A′ has at least one cavity dock 313 and 314 to hold at least one adjusting knob 311 and 312. They are used to adjust and control intake airflow passing through air inlets 412 and 422 of the air pumps 41 and 42, thereby to control the discharged airflow.

In short, the invention adopts a muffling chamber located on an outer bottom side of the air pump base to reduce noise without increasing the size of the air pump assembly. As a result, the casing can also be shrunk. 

1. An air pump for an aquarium comprising a casing and at least one air pump assembly located in the casing, wherein: the casing includes: a upper cap which has a hollow housing chamber; and a base which is coupled with the upper cap to form the casing, and has an inner side to install the air pump assembly, at least one opening and a muffling chamber located on an outer bottom side, the muffling chamber having a hollow chamber formed by indenting the outer bottom side and covered by a bottom lid, and having a plurality of partitions to divide the chamber into a plurality of small air compartments, the neighboring air compartments communicating with each other through vents to form at least one circuitous path for airflow which is discharged through an air discharge duct.
 2. The air pump of claim 1, wherein the air pump assembly includes at least one air inlet and at least one air delivery duct which runs through a plug and anchored in the opening of the base.
 3. The air pump of claim 1, wherein the upper cap has an inner wall which has a plurality of fastening struts located therein, each of the fastening struts having an internal screw thread.
 4. The air pump of claim 1, wherein the upper cap has at least one cavity dock to install at least one adjusting knob. 